This invention relates to a vapor cooling device for cooling an electric device such as a semiconductor device through the utilization of the phase change of a condensible coolant, for example, FREON (trade mark).
It is well known that vapor cooling systems utilizing the heat transfer due to the boiling of a condensible coolant such as FREON (trade mark) exibit extraordinarily excellent cooling characteristics as compared with cooling systems previously employed for electric devices. Recently there have been developed cooling devices for cooling electric devices through the utilization of the heat transfer which have excellent cooling characteristics.
In vapor cooling devices previously developed for cooling semiconductor devices, the stack of semiconductor elements and alternating heat dissipation blocks has been immersed in a body of condensible coolant in the form of its liquid phase charged into a container forming a closed coolant loop with the associated condenser. Thus it has been required to electrically connect the stack to an external electric device through electrically insulated terminals extending through and sealed in the wall of the container. In order to ensure a closed coolant loop, the insulated terminals must have have good reliability. Also in high capacity rectifiers, the stack should fulfil the requirements for the current rating and voltage withstanding property corresponding to the ratings thereof. For example, the stack should have a current rating of several thousands of amperes and withstand a voltage of several thousands of volts.
Further upon any one of the semiconductor elements and/or its accessories being damaged so that they or it must be replaced by new ones or one respectively, it has been required to break the closed coolant loop followed by the replacement. Since the closed coolant loop including the container and condenser is required to be well sealed, the same has included seal welds. Thus a cutting machine has been inevitably used to break the container. Also the removal of the coolant from the container has been attended with difficulties.
Accordingly it is an object of the present invention to provide a new and improved vapor cooling device for an electric device having an excellent performance in which the disadvantages and difficulties of the prior art systems as above described are eliminated.
It is another object of the present invention to provide an improved vapor cooling device most suitable for cooling a planar semiconductor element or elements.